Heating problem

[Bezz!]

I have a vectra cdti 1.9 2006 reg my question is about the engine heating Needle it dosnt stop it goes up to 93'c and the after a while down to 85'C it does it all the time can sombody tell me why ! And it uses mor diesel when it's on 93'c can sombody explaine and help me thnx

[Big Sig]

When moving or when stopped? if its when stopped its normal as thats about when the fans cut in.

[bygumlad]

Its just the thermostat opening and closing to me.

[Bezz!]

Yeah that's the the thing even if I drive it does it.

[bygumlad]

The needle on mine does go up and down but is relevant to driving conditions, i.e. when accelerating on motorways its starts to rise then when coasting it will drop. Is this what is happening in your case or is there no pattern to it, seems an odd one if it is just spontaneous, may be a faulty temp sender unit.

[bappy]

my 1.9 never goes over 80.... rarely actually reaches 60...

[Robsey]

my 1.9 never goes over 80.... rarely actually reaches 60...

Your thermostat has stuck in the open position...however, if it NEVER goes over 80, even when stuck in traffic, then I would query the temp sender.

Regarding intermittent high and then low readings,
This could be a lack of coolant, going round the engine, so when flow is reduced the engine warms up, and when the limited amount of water goes back round it's cycle past the sender, it cools suddenly, and then the cycle repeats...

Otherwords check your coolant level, top up if necessary and remedy any potential leaks before you over-heat and warp your cylinder head.

Had this a long time ago in my cavalier

[bappy]

interesting.. cheers. fluid level is where it should be. sometimes does go over 80 but only in traffic uphill for ages in warm weather, then it doesnt go over 90. is this bad for the engine? should i replace my thermostat?

ta.